独塔四索面斜拉桥主梁非对称悬浇施工技术

Construction Technique of Asymmetric Suspension Casting of Main Girder of Cable-stayed Bridge with Four Cable Faces in Single Tower

番海大桥为塔梁固结的独塔四索面斜拉桥,桥梁一侧跨越道路,另一侧跨越河流。为保证结构安全,主梁采用非对称悬臂浇筑施工,桥梁的线形与应力变化较大,因此需要保证桥梁结构安全的前提下通过不平衡配重、体外施加临时预应力束的方法来调整桥梁的施工平衡。为此本文提出一种无需配重和免施加临时预应力束的主梁独塔四索面斜拉桥主梁非对称悬浇施工技术。即先搭设西侧主梁满堂支架,同时浇筑主塔节段,再进行东侧分节段挂篮悬臂施工。工程实例表明,在复杂的地形地势的情况下,采用主梁非对称悬浇施工,不但能满足结构设计规范要求,并能够缩短施工工期、降低工程造价和施工难度,保证施工安全。

The Panhai Bridge is a single-tower,four-cable plane cable-stayed bridge with pylons and beams.In order to ensure the safety of the structure;the main girder is constructed by asymmetric cantilever pouring,and the line shape and stress of the bridge vary greatly.Therefore,it is necessary to adjust the bridge's performance by unbalanced counterweight and externally applied temporary prestressed beams under the premise of ensuring the safety of the bridge structure construction balance.For this reason,this paper proposes an asymmetric cantilever construction technology for the main girder of a four-cable plane cable-stayed bridge with a single tower and no need of counterweight and temporary prestressing.That is,the west side of the main beam full hall bracket is first erected,and the main tower section is poured at the same time,and then the east side sectioned hanging basket cantilever construction is carried out.The engineering example shows that in the case of complex terrain,the use of asymmetrical cantilever construction of the main girder can not onlymeet the requirements of structural design specifications;but also shorten the construction period,reduce the project cost and construction difficulty,and ensure construction safety.